Effect of Lactobacillus administration on gastrointestinal disturbances in a traveller's diarrhoea situtation involving UN soldiers in Lebanon.

Conway P, 2002 VRI Biomedical Stability Study 010 Lactobacillus fermentum PCC.

Conway P, 2002 VRI Biomedical Stability Study S151 Lactobacillus fermentum PCC"

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"Effect of Lactobacillus administration on gastrointestinal disturbances in a traveller's diarrhoea situation involving US soldiers in Lebanon

Summary

Swedish soldiers in the United Nations Peace Corps in Lebanon (UNIFIL - role is humanitarian and protection of local people) are exposed to an increased risk of diarrhoea and digestive tract disturbances as a result of dietary changes and stress. It has been proposed that the prophylactic use of yoghurt-type bacteria as a probiotic preparation may protect the soldiers against many digestive tract pathogens, which induce diarrhoea. Lactobacillus fermentum PCC (PCC) and Lactobacillus acidophilus DOCIDUS [DOCIDUS, Semper] (DOCIDUS) were selected as potential protectors against enterotoxigenic pathogens. The Swedish soldiers were chosen as an ideal study group because they are generally homogenous in terms of age, physical fitness and diet. The soldiers were divided into three test groups receiving capsules A, B and C containing either placebo (gelatin capsules containing starch), PCC or DOCIDUS and were allocated to volunteers according to a randomly generated code in a double blind study. Participation involved taking two capsules per day for one month and subsequently completing a personal evaluation form.

Greater than 60% of soldiers receiving a placebo suffered gastrointestinal disturbances, and predominantly diarrhoea. PCC provided protection against gastrointestinal disturbances with the incidence reduced by 50% in that group compared with the group receiving placebo. In those soldiers receiving PCC and suffered from diarrhoea, the severity was less for those soldiers receiving placebo who suffered from diarrhoea.

Background

In the healthy adult, the normal bacteria in the digestive tract are very stable and most often protect the host from intestinal pathogenic bacteria (Hentges, 1983). Factors such as dietary change and stress (Tannock, 1983) have been shown to affect the balance of normal digestive tract bacteria, thereby pre-disposing the host to infection by bacteria which induce diarrhoea, such as enterotoxigenic E.coli, Salmonella and Campylobacter. Recent studies support the concept that oral dosing with yoghurt-type bacteria, namely Lactobacillus are able to produce metabolites, which are directly inhibitory to the growth of the intestinal pathogenic bacteria (Reference).

Translocated soldiers on duty as peace-keepers in dangerous regions far from their homes are exposed to an increased risk of suffering abdominal disturbances such as diarrhoea. This may be a result of changes in diet as well as exposure to stress. This is illustrated by the fact that up to 70% of the American soldiers in "Operation Desert Storm" (a 6-week operation by US defense forces against the Iraqi invasion of Kuwait in 1992) were affected by diarrhoea induced by enterotoxigenic E.coli.

Traveller's diarrhoea (ut disturbances, predominantly diarrhoea, affecting tourist visiting unfamiliar regions and eating local food and beverages. While some of the preparations tested in the past have not been successful against traveller's diarrhoea, a new generation of such preparations is emerging (Conway 1989; Conway and Henriksson 1993). These new preparations contain specifically selected strains of Lactobacillus with demonstrable biological activity against the intestinal pathogenic bacteria. In addition, strains have the capacity to grow and produce within the digestive tract, the metabolites which inhibit the growth of the pathogenic bacteria.

PCC was selected in a preliminary study and has been extensively characterised in vitro. DOCIDUS is already a commercially available pharmaceutical product in Sweden and has been shown to be biologically active in humans (Lidbeck 1991).

Experimental Design

Over a period of one month soldiers in the study were given two gelatin capsules daily containing PCC, DOCIDUS or a placebo (gelatin capsules containing starch). All the capsule types appeared the same. Bottles containing capsules were numbered sequentially from 1 to 300, and there were no other identifying features. Allocation of numbers and capsule types to individuals was according to a randomly generated code in a double blind study, and individuals were not aware of which capsules they were taking. The double blind was coded and the code was not revealed until completion of data evaluation. Lactobacillus acidophilus is already approved for human consumption and is presently available through pharmacies as DOCIDUS.

Soldiers in the study were randomly assigned to three equal groups A, B and C and received capsules of either PCC, DOCIDUS or placebo (n=300). Soldiers received 1010 cfu/day and commenced the study three days prior to departure and continued dosage for an additional four weeks. At the end of each week they completed a questionnaire. The study was overseen by the army medical staff. Good compliance was noted.

Results

Greater than 60% of soldiers receiving placebo suffered gastrointestinal disturbances, and predominantly diarrhoea. PCC provided protection against gastrointestinal disturbances with the incidence reduced by 50% in that group compared with the group receiving placebo. In those soldiers receiving PCC and suffered from diarrhoea, the severity was less for those soldiers receiving placebo who suffered from diarrhoea.